C語言雙向鏈表 快速排序

/********************************************************************
* File Name  : quick_sort.c                                                                 *
* Created   : 2007/05/08                                                                      *
* Author   :    SunYonggao                                                                   *
* Description  :  對雙向鏈表進行快速排序
*********************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

//定義類型 所有的排序例子中都是用的int作為data
typedef int elemType;     

//傳回值
#define RET_SUCCESS   ( 1  ) 
#define RET_FAILED   ( 0  )  

//定義鏈表的長度
#define  LIST_MAX_SIZE      (10)

//定義鏈表申請記憶體不夠時報錯資訊
#define NO_MEMORY   printf("Error! Not enough memory!/n");exit(1)

//雙向鏈表結構體定義
typedef struct tagDuNode_t
{
 elemType data;     
 struct tagDuNode_t * pstNext; 
 struct tagDuNode_t * pstPrior;
}duNode_t;

//初始化雙向鏈表
int initDuList(duNode_t ** pstHead)
{
 int iRet = RET_SUCCESS;
 int iCir = 0;
 duNode_t * pstTmp1 = NULL;
 duNode_t * pstTmp2 = NULL;
 
 //初始化前端節點
 * pstHead = (duNode_t *)malloc(sizeof(duNode_t));
 (* pstHead)->pstPrior = NULL;
 (* pstHead)->pstNext = NULL;
 if ( !pstHead )
 {
  NO_MEMORY;
 }
 pstTmp1 = * pstHead;
 //鏈表初始化
 srand( time(NULL) );//隨機數
    for( iCir = 0; iCir < LIST_MAX_SIZE; iCir++ )
 {
  pstTmp2 = (duNode_t *)malloc(sizeof(duNode_t));
  if ( !pstTmp2 )
  {
   NO_MEMORY;
  }
  //賦初值
  pstTmp2->data = rand() % LIST_MAX_SIZE;
  pstTmp2->pstNext = NULL;
  pstTmp1->pstNext = pstTmp2;
  pstTmp2->pstPrior = pstTmp1;
  pstTmp1 = pstTmp2;
 } 
 return iRet;
}

// 列印鏈表 鏈表的data元素是可列印的整形    
int showDuList(duNode_t * pstHead)
{
 int iRet = RET_SUCCESS;
 duNode_t * pstTmp = pstHead->pstNext;
 if ( NULL == pstHead )
 {
  printf("鏈表的前端節點是空/n");
  iRet = RET_FAILED;
 }
 else
 {
  while ( pstTmp )
  {
   printf("%d ", pstTmp->data);
   pstTmp = pstTmp->pstNext;
  }
  printf("/n");
 }
 return iRet;
}

/* 刪除包括前端節點在內的所有的節點. 07/04/28  */
int destroyList(duNode_t * pstHead)
{
 duNode_t * pstTmp = NULL;   /* Temp pointer for circle  */
 int iRet = RET_SUCCESS;
 if ( !pstHead )
 {
  printf("Error! pstHead is null/n");
  iRet = RET_FAILED;
 }
 else
 {
  while ( pstHead )  /* Free  nodes      */
  {
   pstTmp = pstHead;
   pstHead = pstHead->pstNext;
   free(pstTmp);
  }
  pstHead = NULL;
 }
 return iRet;
}/* End of destroyList----------------------------------------------*/

//正確的快速排序 2007/05/09
/*
 一趟快速排序的具體做法是：附設兩個指標low和high(即第一個和最後一個指標),
 他們的初值分別為low和high設樞軸(一般為low的值pivot)記錄的關鍵字
 (即本例子中的整形data)為pivot，則首先從high所指位置
 起向前搜尋到第一個關鍵字小於pivot的記錄和樞軸記錄交換，然後從low所指位置起
 向後搜尋，找到第一個關鍵字大於pivot的記錄和樞軸記錄相互交換，重複這兩步直
 至low = high為止。
*/
duNode_t * partion(duNode_t * pstHead, duNode_t * pstLow, duNode_t * pstHigh)
{
 elemType iTmp = 0;
 elemType pivot = 0;
 if ( !pstHead )
 {
  printf("錯誤，前端節點為空白！/n");
  exit(1);
 }
 if ( !pstHead->pstNext )
 {
  return pstHead->pstNext;//就一個元素
 } 
 pivot = pstLow->data;
 while ( pstLow != pstHigh )
 {
  //從後面往前換
  while ( pstLow != pstHigh && pstHigh->data >= pivot )
  {
   pstHigh = pstHigh->pstPrior;
  }
  //交換high low
  iTmp = pstLow->data;
  pstLow->data = pstHigh->data;
  pstHigh->data = iTmp;
  //從前往後換
  while ( pstLow != pstHigh && pstLow->data <= pivot )
  {
   pstLow = pstLow->pstNext;
  }
  //交換high low
  iTmp = pstLow->data;
  pstLow->data = pstHigh->data;
  pstHigh->data = iTmp;
 }
 return pstLow;
}
//快排
void quick_sort(duNode_t * pstHead, duNode_t * pstLow, duNode_t * pstHigh)
{
 duNode_t * pstTmp = NULL;

 pstTmp = partion(pstHead, pstLow, pstHigh);
 if ( pstLow != pstTmp )
 {
  quick_sort(pstHead, pstLow, pstTmp->pstPrior);
 }
 if ( pstHigh != pstTmp )
 {
  quick_sort(pstHead, pstTmp->pstNext, pstHigh);
 }
 
}
void main()
{
 duNode_t * pstHead = NULL;
 duNode_t * pstHigh = NULL;
 duNode_t * pstTmp = NULL;
 initDuList(&pstHead);   //初始化
 printf("Before sorting:/n");
 showDuList(pstHead);   //列印
 pstTmp = pstHead->pstNext;
 while ( pstTmp->pstNext )
 {
  pstTmp = pstTmp->pstNext;
 }
 pstHigh = pstTmp;//找到最後一個節點的指標用於快排時
 quick_sort(pstHead, pstHead->pstNext, pstHigh);//快排序
 printf("After sorting:/n");
 showDuList(pstHead);
 destroyList(pstHead);
 pstHead = NULL;
}
/* End of file ----------------------------------------------------*/